Reporting of Channel Quality Indicator Measurement

Last updated: 2010-03-10

Reporting of Channel Quality Indicator (CQI) Measurement Description

3GPP TS 34.122 9.3.3 states "The reporting accuracy of channel quality indicator (CQI) under AWGN environments is determined by the reporting variance and the BLER performance using the transport format indicated by the reported CQI median."

The Reporting of Channel Quality Indicator measurement consists of two main parts, which run in sequential order:

Part 1: CQI Variance Test

The test set starts the HSDPA block transmission with a fixed TBS value. The test set then decodes the CQI reports from the UE and transmits new blocks with the transport block size and modulation scheme recommended by the UE (the test set works at the VRC mode, see HS-DSCH Config). The HSDPA block transmission and UE CQI recording continues until the Number of CQI Reports to test is gathered. The test set calculates the Median CQI that meets the requirement of 50% distribution from the lower RTBS side (see more in 3GPP TS 34.122 s9.3.3). If at least Number of CQI Reports to test *Percentage of CQI values within range are within the required range, the measurement continues with Part 2, otherwise the entire test fails.

Part 2: BLER at Median CQI

The test set transmits the TBS according to the median-CQI value derived in Part 1 until the Number transmitted at Median CQI to test is gathered. The test set then calculates the Block Error Ratio (BLER) by ( NACK + statDTX) / (ACK + NACK + statDTX).

The HSDPA Reporting of Channel Quality Indicator measurement is only allowed to be run in the following conditions:

Operating Mode is Active Cell;
Paging Service Type is RB Test Mode;
Channel Type is 12.2k RMC + HSDPA.

The HSDPA Reporting of Channel Quality Indicator measurement can not be performed in concurrence with the HSDPA Block Error Ratio (HBLER) measurement.

Reporting of Channel Quality Indicator (CQI) Measurement Parameters

Number of CQI Reports to test

Sets the number of CQI reports to be gathered for the CQI Variance Test (Part 1 of the Reporting of Channel Quality Indicator measurement).

GPIB Command: SETup:THCQuality:CQIReports[:COUNt]

Percentage of CQI values within range

Sets the percentage of values that must be in the range (Median_CQI-x) to (Median_CQI+x) used during CQI Variance Test (Part 1 of the Reporting of Channel Quality Indicator measurement), where x refers to the Permitted CQI range from median.

GPIB Command: SETup:THCQuality:CQIValues:WRANge

Number transmitted at Median_CQI to test

Sets the number of CQI reports to be gathered for the BLER at Median CQI test (Part 2 of the Reporting of Channel Quality Indicator measurement).

GPIB Command: SETup:THCQuality:TRANsmit:MCQI[:COUNt]

Permitted CQI range from median

Sets the x parameter as defined in the standard. The pass condition for the CQI Variance Test (Part 1) is: the CQI indicators of at least Number of CQI Reports to test *Percentage of CQI values within range are in the range (Median CQI - x) ≤ Median CQI ≤ (Median CQI + x).

GPIB Command: SETup:THCQuality:RANGe:FMEDian

BLER criteria for transmitted at Median_CQI

Sets the maximum allowed BLER for median reported CQI (Part 2 of the Reporting of Channel Quality Indicator measurement). The pass condition for the Part 2 is: the BLER at Median CQI is less than this value.

GPIB Command: SETup:THCQuality:BLERatio:TRANsmit:MCQI

Measurement Timeout: see Measurement Timeout.

Reporting of Channel Quality Indicator (CQI) Measurement Results

Part 1: CQI Variance Results.

Median_CQI

This is the Median CQI value as specified by 3GPP TS 34.122 9.3.3.

GPIB Command: FETCh:THCQuality:CQINdicator:MEDian?

CQI in Range (%)

This result is the percentage of CQI values reported from the UE that are in the range of Median_CQI-x to Median_CQI+x, where x refers to the Permitted CQI range from median.

GPIB Command: FETCh:THCQuality:CQIReports:WRANge?

Reports at Median_CQI±0/1/2/3

This results reflects how many reports are gathered at Median_CQI, Median_CQI±1, Median_CQI±2, and Median_CQI±3, respectively. The CQI report distribution generated by the test set during the CQI Variance Test (Part 1) can be obtained using the GPIB query: FETCh:THCQuality:CQIReports:DISTribution?

GPIB Command: FETCh:THCQuality:CQIReports:CQIMinus1|2|3?, FETCh:THCQuality:CQIReports:CQIPlus0? and FETCh:THCQuality:CQIReports:CQIPlus1|2|3?

Part 2: Block Error Ratio (BLER) at Median CQI

BLER at Median CQI

This is the Block error rate when the test set transmits blocks at Median CQI value (part 2). The overall block number transmitted at Median CQI is Number transmitted at Median CQI to test.

GPIB Command: FETCh:THCQuality:BLERatio:TRANsmit?

Blocks Tested

Indicates how many blocks are tested at the moment for the entire measurement.

GPIB Command: FETCh:THCQuality:BLOCks?

How Do I Make a Reporting of Channel Quality Indicator (CQI) Measurement?

The following procedure performs the 3GPP TS34.122 9.3.3E Reporting of HS-DSCH Channel Quality Indicator-2.8Mbps UE class, Test 1, as an example.

Note: For TS34.122 9.3.3E, the standard also requires the multipath fading simulator and external AWGN,, which are not included in this procedure.

Initial conditions

Ensure that the test set has been properly calibrated (see Calibrating the Test Set).
Connect the UE to the front panel RF IN/OUT port.
Set call parameters as following:
[F7 in Call Parms 1 of 3] Set the Cell Power to -63 dBm (default value).
[F8/F9 in Call Parms 1 of 3] Set the Paging Service to RB Test Mode, and Channel Type to 12.2k + HSDPA.
[F11 in Call Parms 1 of 3] Set the HSDPA parameters.

[F7 in HSDPA Parms] Set HS-DSCH Config to VRC, leave other HSDPA RB Test Mode settings as default.
[F8 in HSDPA Parms] Set Number of Transmissions to 1, leave other MAC-hs Parameters as default.
Leave other HSDPA Parameters as default.
[F2 in Call Control 2 of 3] In Cell Parameters, set the PS Domain Information to Present.
Power the UE on and wait for it to be registered.
[F3 in Call Control 1 of 3] Press Originate Call. Wait for the Active Cell area to be Connected.
The test set will automatically configure the channels according to the UE Reported HS-DSCH Category. For example, UE Reported HS-DSCH Category of 15 indicates 2.8 M UE class (9.3.3E Reporting of HS-DSCH Channel Quality Indicator-2.8Mbps UE class), and the test set will automatically configure the downlink channels by 3GPP TS 34.122 Table 9.3.3E.1 as below (The following parameters are set independently in other steps: Number of HARQ Process, Number of Transmission and Îor/Ioc).

Procedure

Press the Measurement selection key.
Select Reporting of Channel Quality Indicator.
Select HSDPA Reporting of CQI Setup (F1). Configure the setup parameters as shown in the figure below (the default settings are in accordance with 3GPP TS 34.122 9.3.3E):

Press the START SINGLE key.
Verify that the overall test result is Pass.

Per 3GPP TS34.122 9.3.3E, the minimum requirement for this test case is as below: